1. Field of the Invention
The present invention relates to compressed gas powered guns, and more particularly, to trigger mechanisms used for firing such guns.
Compressed gas guns employing CO.sub.2 or compressed air to fire projectiles are well known in the art. The projectiles typically comprise arrows or harpoons, and also include gelatin-encased balls which are filled with a liquid such as paint. These guns generally are activated by a complex mechanical valving system which utilizes conventional hammer and sear-type triggering mechanisms which are modified for gas discharging valves. The impact action of the hammer is converted to a translational movement of the valve to result in a gas discharge through the valve stem to fire the projectile.
2. Discussion of the Prior Art
In the prior art, various trigger mechanisms for gas powered guns are disclosed which utilize complex spring-biased constructions to open and close a valving system to effect the gas discharge to fire the projectile from the gun. These trigger arrangements, however, are subject to several disadvantages, and in many cases require specialized assembly in manufacture and result in increased manufacturing costs. Furthermore, the complexity of the trigger mechanism may eventually result in a breakdown of the interconnections of the numerous moving parts, often requiring expensive and time-consuming repairs to the gun.
Hale, U.S. Pat. No. 3,788,298, discloses a gun for firing projectiles such as paint balls using a compressed gas source such as a CO.sub.2 cartridge. A conventional valve stem is biased by a spring into a closed position, while a hammer member is spring biased away from valve stem and locked in a ready position by a pivotable sear member. A spring biased finger actuated trigger is pulled rearward to release the sear, which in turn releases the hammer, which is propelled rearward by the spring to impact against a flange on the valve stem. This impact overcomes the biasing force of the valve stem spring to force the stem rearward to allow for discharge of compressed gas through the valve stem to propel a paint ball projectile.
Chiba, U.S. Pat. No. 4,163,439, discloses a trigger mechanism for opening a gas delivery valve in a compressed gas powered gun. A pivotable finger actuated trigger and latch member are provided which engage a valve rod. The valve rod is spring biased to close a gas passage which leads to a gas chamber. The chamber is pressurized by pumping compressed gas into the chamber at a pressure which overcomes a spring biased check valve. When the trigger is pulled, the pressure in the chamber overcomes the rod spring force to move the rod to a position which vents the gas in the chamber to fire a projectile.
Ford et al., U.S. Pat. No. 4,865,009, discloses a gas discharge system for an airgun in which compressed gas is provided to a discharge chamber prior to firing of the gun. As the trigger is pulled, a pivotable release mechanism is moved out of engagement with a spring biased block, and the block is forced rearward. As the block moves, a shaft member is moved with the block past a discharge port so that compressed gas is discharged from the chamber to fire a projectile.
Dobbins et al., U.S. Pat. No. 4,936,282, discloses a gas powered gun for firing projectiles such as paint balls. A cocking and loading mechanism is provided, as well as a hammer and sear-type trigger mechanism for firing the gun. As the trigger is pulled, the sear pivots away from the spring biased hammer, which moves rearward, which also moves a bolt member rearward to allow a paint ball to drop into the barrel. As the hammer continues to move rearward, the valve stem flange is contacted and driven rearward to discharge compressed gas through the stem to fire the paint ball projectile.
The novel compressed gas gun pursuant to the present invention obviates the disadvantages encountered in the prior art and provides an efficient triggering mechanism for actuating the gun which eliminates many moving parts, resulting in an easy to manufacture and relatively inexpensive device. The trigger mechanism provides a camming action which urges the valve stem against the force of a biasing spring to communicate the stem passage with the gas chamber to instantaneously propel a projectile such as a paint ball from the gun.